Temperature control device for furnaces



1936. IR. M. BAKER TEMPERATURE CONTROL DEVICE FOR FURNACES 2Sheets-Sheet 1 Filed Aug. 23, 1934 Feb 49 39360 R. M. BAKER TEMPERATURECONTROL DEVICE FOR FURNACES F l ug- 5, 1934 2 Sheets-Sheet 2 PatentedFeb. 4, 1936 UNITED STATES PATENT OFFICE TEMPERATURE CONTROL DEVICE FORFURNACES '7 Claims.

This invention relates to temperature control devices for furnaces, butparticularly to an automatic device for controlling one or more dampersin accordance with the heat generated by the furnace.

An object of this invention is to produce a new and improved furnacetemperature control or regulatonwhich can be initially or from time totime adjusted in a simple manner to the temperature desired, and willthereafter operate automatically to obtain a substantially uniformtemperature of a predetermined degree. Another object is to produce afurnace temperature regulator which has the novel features ofconstruction, operation and arrangement hereinafter described.

Further objects and advantages will hereinafter appear, and, forpurposes of illustration, an embodiment of the invention is shown on theaccompanying drawings, in which:

Figure 1 is a fragmentary side elevational view of a furnace with aportion of the casing and body of the furnace broken away to show theinterior thereof equipped with my new temperature regulator;

Figure 2 is a transverse sectional view on the line 2-2 of Figure 1showing the baffle construction of the smoke consumer;

Figure 3 is an enlarged sectional view on the line 33 of Figure 1showing the thermally actuated rocking bar;

Figure 4 is a sectional View on the line 4--4 of Figure 3;

Figure 5 is an enlarged fragmentary front elevation of an upper endportion of the furnace casing showing the manual control for thethermally actuated bar; and

Figure 6 is a fragmentary side elevational view of the upper end'of thefurnace casing showing the blower control.

The illustrated embodiment of the invention comprises a furnace body orshell ll] of the usual steel construction, or of such material, as toexpand or contract thermally, and enclosing the body I is a casing orjacket ll of sheet metal, or other suitable material.

Mounted on the upper end of the furnace body is a pointed fulcrum l2 onwhich rests a lateral extension l3 of a bar M, which extendstransversely of the upper portion of the casing I I. The lateralextension [3 is preferably disposed centrally of the bar 14 and the baris rockable in response to thermo-expansion or contraction of thefurnace body Ill. The opposite ends of the bar [4 are considerablyreduced in size and are rounded, one end being rockably mounted in aplate l having a stud l6 suspended from a bracket IT, a nut l8adjustably holding the plate l5 in the desired position. Initially, thevertical position of the plate [5 is adjusted by turning the nut [8.

The opposite rounded end of the bar I4 is 5 mounted in and free to rockrelative to one end of an adjusting arm I9. The arm I9 is pivoted at 20in an embossed portion of a bracket plate 2|, which is secured to theoutside of the casing II. The opposite end of the arm [9 extends outsideof 10 the casing ll through a vertically elongate slot 22. Extendinglaterally from the arm I9 is a flange or tooth 22 which may be movedinto selective engagement with one of the notches 23 on a calibratedindicator plate 24. It will be noticed that this plate is calibratedfrom zero to seventy degrees, and the arm [9 is adjusted with respect tothis plate in accordance with the temperature of the air outside of thebuilding. For example, if the outside temperature is 25 F. the arm I9 isadjusted so that the tooth 22 is inserted in the notch corresponding tothe 25 calibration on the plate 24, and, as will hereinafter appear,this adjusts the thermally actuated bar 14 properly to maintain asuitable temperature within the room 25 to compensate for the cooleroutside temperature.

Fixed to the bar l4 between the lateral extension l3 and one end of thebar, is an arm 25 to the outer end of which is pivoted a depending link26. The lower end portion of the link 26 is provided with a series ofholes 21 selectively to receive a bolt for connection to an arm 28, theinner end of which is provided with a weight 29. The opposite endportion extends through the case I I and is pivotally mounted at 30, andthe free end thereof is connected by a chain 3| to a draft damper 32 ofthe usual form disposed at the lower part of the furnace, in thisinstance being mounted on the door 33 of the ash pit. The arm 28 is alsoconnected by a slotted link 34 to a door 35, which controls the passage36 leading to a vertically disposed bell-shaped smoke consumer 31 inwhich is disposed a core 38 having a series of radial baflles or blades39 suspended in place by a bolt 40.

It will be understood that when the door 35 is open, air is drawntherethrough and broken up by the baffle plates 39 to effect morecomplete combustion of fuel within the combustion chamher. It will beunderstood that the weight 29 is sufficient substantially to compensatefor the weight of the dampers 32 and 35 in order to maintainsubstantially a balanced condition and to enable slight verticalmovement of the arm 26 to effect the desired opening or closing movementto these dampers.

If desired, a blower may be provided for forcing air through thefurnace, and thereby increase the circulation of air through thefurnace. Such blower is not shown on the drawings, but any well knowntype of electrically driven blower may be used for this purpose and maybe operated by anarm 4|, which is fixed at one end to the end of the bar4 adjacent the bracket plate IS. The opposite end of the arm 4| may beL-shaped and is formed with a looped end to engage a switch arm 42. Uponrocking movement of the arm I 4 in one direction, the arm 4| will bemoved in such manner as to move the switch arm 42 to close an electriccircuit for energizing the blower, and actuation in the oppositedirection will move the switch arm 42 to open the blower circuit.

In operation it is apparent that the expansion or contraction of thefurnace body I!) operates to rock the bar l4, and this movement istransmitted by links and levers to the doors 32 and 35, which may beconcommitantly opened or closed to increase or diminish the draft to thecombustion chamber. The amount of such movement, it is apparent, iscontrolled by the adjustment of the control arm I9, and such adjustmentis dependent upon the outside temperature.

It is to be understood that the above description is to be given by wayof illustration and not of limitation, and numerous changes in detailsof construction and operation may be effected without departing from thespirit of the invention, especially as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and a draft damper, saiddevice comprising a fulcrum on the top of said body responsive tothermal expansion or contraction of said body, a bar extending acrosssaid housing, a pivotal mounting for opposite ends of said bar enablingaxial turning movements thereof, a lateral extension on an intermediateportion of said bar resting on said fulcrum, lever and link meansconnecting said bar with said damper for actuating same upon turningmovements of said bar, and means for raising or lowering one end of saidbar for predetermining the action thereof.

2. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and draft damper, saiddevice comprising a fulcrum on the top of said body responsive tothermal expansion or contraction of said body, a bar extending acrosssaid housing, a pivotal mounting for opposite ends of said bar, alateral extension on an intermediate portion of said bar resting on saidfulcrum, lever and link means connecting said bar with said damper foractuating same upon rocking movements of said bar, an arm pivotedadjacent one end and engaging said bar at such end, the opposite end ofsaid arm extending outside of said housing to enable same to be adjustedfor predetermining the action of said bar.

3. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and a draft damper, saiddevice comprising a fulcrum on the top of said body responsive tothermal expansion or contraction of said body, a bar extending acrosssaid housing, a pivotal mounting for opposite ends of said bar, alateral extension on an intermediate portion of said bar resting on saidfulcrum, lever and link means connecting said bar with said damper foractuating same upon rocking movements of said bar, an arm pivotedadjacent one end and engaging said bar beyond the pivotal point thereof,the free end of said arm extending outside of said housing, a plate onsaid housing calibrated in degrees of temperature, and means on saidplate for receiving the free end of said arm in selective position.

4. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and a draft damper, saiddevice comprising a fulcrum on the top of said body responsive invertical movement to changes in thermal conditions of said body, a barextending across said housing, a pivotal mounting for opposite ends ofsaid bar enabling axial turning movements thereof, a lateralintermediate extension on said bar resting on said fulcrum, and leverand link means connecting said bar with said dampers for actuating samefrom turning movements of the former.

5. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and a draft and smokeconsumer dampers, said device comprising a fulcrum on the top of saidbody responsive to thermal expansion and contraction of said body, a barextending transversely of said housing, a mounting for opposite ends ofsaid bar to afford axial turning movements thereof, a lateral extensionon said bar resting on said fulcrum, and operative connections betweensaid bar and dampers to actuate same from rocking movements of theformer.

6. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body and a draft damper, saiddevice comprising a fulcrum on the top of said body responsive invertical movement to changes in thermal conditions of said body, a barextending across said housing, a mounting for opposite ends of said barto afford turning movements thereof, a lateral intermediate extension onsaid bar resting on said fulcrum, and lever and link means connectingsaid bar with said dampers for actuating same from turning movements ofthe former, said lever and link means including a counterbalance forsaid damper.

7. A temperature controlling device for a furnace provided with afurnace body, a housing enclosing said body, a draft damper and anelectric blower control, said device comprising a fulcrum on the top ofsaid body responsive to thermal expansion and contraction thereof, a barextending transversely of the upper end of said housing, a mounting forsaid bar affording axial rocking movements thereof, a lateralintermedlate extension on said bar resting on said fulcrum, and link andlever means operatively connecting said bar and said damper and electricblower control for actuating the latter from rocking movements of theformer.

ROBERT M. BAKER.

